1. Field of the Invention
This invention relates to a voltage detection device for a battery package.
2. Description of the Prior Art
Battery packages used in hybrid automobiles, electric cars, or fuel-cell-powered vehicles preferably include a plurality of battery modules connected in series because a high voltage output reduces transmission loss and provides miniaturization of motors.
In the battery package circuit with a high voltage output, an output voltage of each battery module was measured individually. However, in this case, the maximum voltage potential difference is large because of the series connection, so that the circuit elements in voltage detection device should have high withstand voltage requirements. In other words, a voltage detection device having a circuit structure allowing a low withstand voltage requirement is desired.
The aim of the present invention is to provide a superior voltage detection device for a battery package.
According to the present invention, a first aspect of the present invention provides a voltage detection device for a battery package including high and low voltage groups of battery modules connected in series, said high and low voltage groups including N of said battery modules connected in series, respectively, a positive terminal of said Lth battery module in said high voltage group outputting the highest voltage potential in said battery package when L=1, a negative terminal of said Lth battery module in said low voltage group outputting the lowest voltage potential in said battery package when L=1, 1xe2x89xa6Lxe2x89xa6N;
N junction points;
2N current limiting resistive elements, a positive terminal of said Lth battery module in said high voltage group being connected to said Lth junction point through one of said current limiting resistive elements, a negative terminal of said Lth battery module in said low voltage group being connected to said Lth junction point through another one of said current limiting resistive elements; and
voltage detection means for detecting and outputting voltage potentials at said N junction points.
According to the present invention, a second aspect of the present invention based on said first aspect provides the voltage detection device further comprising N voltage difference detection circuits for detecting and outputting voltage differences between said Lth and (L+1)th junction points, respectively, wherein said Nth voltage difference detection circuit detects a voltage difference between said Nth junction point and a connection point between said high and low voltage groups of battery modules.
According to the present invention, a third aspect of the present invention based on said first aspect provides the voltage detection device further comprising potential difference detection means for detecting and outputting potential differences between voltage potentials at said N junction points and a reference voltage at a connection point between said high and low voltage groups of battery modules.
According to the present invention, a fourth aspect of the present invention based on said first aspect provides the voltage detection device further comprising data processing means for calculating output voltages of said 2N battery modules from said detected voltage potentials, respectively.
According to the present invention, a fifth aspect of the present invention based on said second aspect provides the voltage detection device further comprising data processing means for calculating output voltages of said 2N battery modules from outputs of said N voltage difference detection circuits, respectively.
According to the present invention, a sixth aspect of the present invention based on said third aspect provides the voltage detection device further comprising data processing means for calculating output voltages of said 2N battery modules from said detected potential differences, respectively.
According to the present invention, a seventh aspect of the present invention based on said fifth aspect provides the voltage detection device, wherein said data processing means calculates variations in said output voltages of said 2N battery modules, respectively.
According to the present invention, an eighth aspect of the present invention based on said sixth aspect provides the voltage detection device, wherein said data processing means calculates variations in said output voltages of said 2N battery modules, respectively.
According to the present invention, a ninth aspect of the present invention aspect provides the voltage detection device for a battery package including high and low voltage groups of battery modules connected in series, said high and low voltage groups including N of said battery modules connected in series, respectively, a positive terminal of said Lth battery module in said high voltage group outputting the highest voltage potential in said battery package when L=1, a negative terminal of said Lth battery module in said low voltage group outputting the lowest voltage potential in said battery package when L=1, 1xe2x89xa6Lxe2x89xa6N;
N junction points;
2N current limiting resistive elements, a positive terminal of said Lth battery module in said high voltage group being connected to said Lth junction point through one of said current limiting resistive elements, a negative terminal of said Lth battery module in said low voltage group being connected to said Lth junction point through another one of said current limiting resistive elements; and
voltage detection and operation means for detecting voltage potentials at said N junction points and for obtaining and outputting conditional data of said battery modules from said detected voltage potentials.
According to the present invention, a tenth aspect of the present invention based on the ninth aspect provides the voltage detection device, wherein said voltage detection and operation means comprises N voltage difference detection circuits for detecting voltage differences between said Lth and (L+1)th junction points, respectively, wherein said Nth voltage difference detection circuit detects a voltage difference between said Nth junction point and a connection point between said high and low voltage groups of battery modules to obtain said conditional data from said detected voltage differences.
According to the present invention, an eleventh aspect of the present invention based on said ninth aspect provides the voltage detection device, wherein said voltage detection and operation means comprises potential difference detection means for detecting potential differences between voltage potentials at said N junction points and a reference voltage at a connection point between said high and low voltage groups of battery modules to obtain said conditional data from said detected potential differences.
According to the present invention, a twelfth aspect of the present invention based on the ninth aspect provides the voltage detection device, wherein said voltage detection and operation means comprises calculating means for calculating output voltages of said 2N battery modules from said detected voltage potentials, respectively.